Variable condenser



Sept. 29, 1925. 1,555,634 S. COHEN VARIABLE CONDENSER Filed Nov" 8, 1924 5' Sheets-Sheet l 65 amen Jo's 1510211116 (fa/2 fl/z Sept. 29, 1925.

I s. COHEN VARIABLE CONDENSER Filed' Nov. 8 1924 izz 97%.

37" l I 1/9 I 27 65 i 39 i I5 SheetsSheet 2 snow doc Sept. 29, 1925. 1,555,634

' s. COHEN VARIABLE CONDENS ER Filed Nov. 8, 1924 3 Sheets-Sheet 5 Patented Sept. 29, 1925.

UNITED STATES PATENT OFFICE.

SAMUEL COHEN, OF BROOKLYN, NEW YORK, ASSIGNOR TO GENERAL INSTRUMENT CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

VARIABLE CONDENSER.

Application filed November 8, 1924. Serial No. 748,708.

To all whom it may concern:

Be it known that I, SAMUEL Conan, a citizen of the United States, residing at Brooklyn. county of Kings, and State of New York, have invented a certain new and useful Improvement in Variable Condensers, of which the following is a specification- My invention relates broadly to electrical apparatus and more particularly to a construction of variable electrical condenser.

One of the objects of my invention is to provide a variable condenser having parts of such mechanical design that they may be readily manufactured in large numbers and assembled to form complete condensers on a quantity production basis.

Another object of my invention is to provide a variable condenser housed within a metallic frame and in which the stator plates are completely insulated from the rotor plates by dielectric material formed of quartz, glass or other hard vitreous materials.

Still another object of my invention is to provide a variable condenser construction in which the frame portions may be stamped from sheet material and arranged to support the stator plates centrally within the frame by means of pedestal insulators secured between each of the frame portions and the stator plates.

Still another object of my invention is to provide an arrangement of parts for a variable condenser construction wherein the stator plates are positively spaced one from another by a spacing member which is in' turn supported at each end thereof by a pedestal type of insulator placed in compression by end members which form the rame of the condenser,

Still another object of my invention is to provide means for readily mounting the rotor shaft of a variable condenser between a pair of end plates which form the frame of the condenser.

A still further object of the invention resides in the method of supporting the rotor plates of a condenser by grooving the rotor at a plurality of points spaced one. from another into which grooves the plates may be set and secured in position by upsetting opposite sides of the inset portions of the plates.

A still further object of my invention is rovide a ball bearing mounting for one of the rotor shaft and a screw chuck journal for the opposite end of the rotor shaft whereby the rotor shaft may be centered between the end frames and revolved to a selected position to more the rotor plates between the stator plates.

still further object of my invention is to provide a set of stator and rotor plates die pressed upon such a contour that the shape of the plates permits a uniform variation in capacity as the angular position of th rotor plates is changed with respect to the stator plates.

My invention will be more clearly understood by reference to the following specification and the accompanying drawings in which:

Figure 1 is a plan view of the assembled condenser; Fig. 2 is a side elevation of the condenser illustrating the method of supporting the stator plates on pedestal insulators in compression between the end plates of the condenser; Fig. 3 is a side elevation of the condenser illustrated in Fig. 2; Fig. 4. is a cross sectional view taken through the condenser on line 44 of Fig. 3; Fig. 5 is a plan view representing the method of mounting the rotor plates in the rotary shaft; Fig. 6 is a cross sectional view through the rotary shaft showing the method of inserting the rotor plates Within the rotary shaft and upsetting opposite sides thereof: Fig. 7 is a cross sectional view showing one type of pedestal insulator which i may employ in supporting the stator plates; Figs. 8 and 9 show the construction of each of the rotor plates and the appearance of the opposite upset edges of the plates; Fig- 10 is a cross sectional view taken through another form of pedestal insulator which I may employ 'in my condenser construction; Figs. 11, 12 and 13 show the assembly of a modified construction of condenser employing pedestal insulators for the support of the stator plates of the type shown in Fig. 10; Fig. 14 is a detail view illustrating the construction of rotor shaft employed in the condenser construction illustrate in Figs. 11, 12 and 13; and Fig, 15 illustrates the method of mounting the screw chuck journal for the rotor shaft in one of the metallic end plates for the condenser.

My invention provides a construction oi variable condenser of high electrical and mechanical efiiciency with practically no ligible electrical losses. I secure this hig etudge members m eans o secu ficiency y worm ng e-s at r p at s out of n a w h hem ll c frame at the condenser by means of quartz, glass or other d us ma e a s Su h materia is not subject to drilling or tapping and T have accordingly provided means for interposing this material in the form of pedestals under compression between the spacer members for the stator plates and the metallic end frame.

of the condenser. The metallic end frames are thereby spaced at a considerable distance from the stator plates out of contact with bodies of opposite electrical charge. I also provide a construction of rotor which enables flat plates tobe set into a grooved rotor and opposite edges thereof upset to form a lock with the material of the rotor. I out thestator plates substantially semicircular at one edge with lateral projections at each side enabling them to be supported in spacer members located centrally of the condenser frame and between the pedestal insulators under compression. The other edge of the stator plates is cutaway enabling the rotor shaft to beoperated adjacent the edges of the plates. The edges of the stator plates are th brought. out tothe ends of the plates upon a substantiall straight line. The rotor plates are formed substantially semi-circular at one edge and have opposite es con r g su stantially ith t edges of the stator plates. The selected h p o h pla es enables un fio m va tion in capacity to be obtainfid for the Various angular positions of the rotor plates.

The construction of my variable condenser will be more fully understood by referring to the drawin s in detail. Reference char acters 1 and 2 esignate the end frame plates f e co d n r- The f am pla 1 i P ided with extending tongues 3, i, 5 and 6 while the end, plate 2 is provided with eX-. tending tongues 8, 9., 10 and 11. These are joined in frame-.likeiforrnation by posts 17, 18, 19,20, and 21. Betweenthe extended.

tongue port-ions 3 and. 6-1 provide a bridge memben 12v and correspondingly between the extensions 8 and 11 I provide a bridg mew her 15: The opposite sid o t conde ser frame is-bnilt up in a similar manner, that aidge e r 1 is-placed acmss ex Pensions 4: d. whilea bridg member 16 is placed across extensions 9 and 10. TEE vt e ta or platss'and nsula ing P d stals are: 17 nde comnress nt The stator plates are. represented at 3% having substantially emi c rcu a-r edg s and nd port n w i h xtendintosm rw 33 ins-specie bl ck 32 as represented (dearly= in .igure 7-. f -he spacing, block ism pad at ea h an wonde o' uppont a pedes t recewmg ap- A-cun m mber .1 is posi oned on n en fit 'e s a es memb bsnew. t eas 31? which passes through a washer member 31*. On the opposite end of the spacing member 32 a cup shaped member 29 is te he r dg member 1% a up shaped member 22 is secured b means of screw 24. On the bridge member 16 a'cup shaped member 23 is secured held in position by a screw The cup shaped member 23 may be securely positioned upon the bridge 16 by means of a screw cooperating with the nut 25. Insulators of yrex, glass, quartz, ceramic material or ot er hard vitreous materials are formed in'the shape of short cylindrical posts and are interposed between the cup shaped members 22 and 29 and 31v and 23 as represented at 28 and 30. Each cup shaped member is provided with a plurality of longitudinal slots 31 disposed at a plurality of points about the periphery of the cup shaped members in order to permit the ready insertion ofthe pedestal insulators. The posts 1-8 and 19 at one end of the condenser frame are securely drawn together by means of nuts working on screw threads at each end of the posts thereby drawing the end fram s 1 and 2 together.

with the pedestals 28 and in com ression. A similar construction is provid at the other end of the condenser frame wherein pedestal insulators 38 and 35 are secured between cup shaped members represented at 3.6 a 3- r w v ses 26 2 Poetion the cup shaped members with respect to,

the bridges 12 and 15. The spacer block 37 is secured between the cup shaped members 36 and 43 providing a positive support for the opposite ends of the stator plates. The stator plates are cut away as represented at to secure the shape desired and to enable the rotor to be journaled adjacent the edges of the plates. The rotor comprises a shaft member 52 having an enlarged portion 57 which is grooved at a plurality of points along the length thereof to. enable the rotor plates to he set into the rotary shaft. A pair of longitudinal grooves 59 are prov ded on opposite sides f he otor 57 The rotor plates 49 are provided with a central extension 60 which may bepromoted into the groove 58 formed in the, rotor 57 and hen pposite dges upset as epresen ed at 1 a d, 2 filling he spa es p ovid by the ngitudi al gr v s59 a d look ng th 1:0- tor plates with relation to the rotor shaft. Each rotor plate is substantially senn-cirula a ne g a d i P Q1dd W1-, a traig e g h ther edge fset nd then onne te h the sem -circular edge repr sente by h St a 1 lin 6 .Thisshapein cooperation with t e shapep he s atorplqtes 3t em liles un form v ne; s in emen be a. 2 s spring, Pres d a fla pring 68 cur d gai s he end were 2- Tb tb fled th lefii m ned The- M re nd by mean 0 52 is 'ournaled in a bearing formed by a spring chuck 56 secured in the end frame portion 1 by means of nuts 54 and 55. The spring chuck is scrcw threaded at 53 enabling it to be adjusted longitudinally with respect to the end frame 1 to form an adjustable bearing for the rotor! The adjust.- ment of the chuck 56 is accomplished by loosening nuts 54 and 55 and sliding the chuck longitudinally with respect to the end plate 1. The tongue 66 cooperating with the longitudinally extending groove maintains the chuck 56 in an accurate aligned position with respect to the shoulder 51 of the rotor shaft 52. When a position is reached Where the rotor plates 49 are accurately positioned with respect to the stator plates 34, the nuts 54 and 55 are tightened, securing the chuck 56 in positionj In Figs. 11, 12 and 13 I have illustrated a modified construction of condenser in which porcelain pedestal insulators 40, 41, 42 and 39 are employed with a large dielectric area for substantially eliminating electrical losses. The rotor shaft 52 in this construction may be provided with a shoulder 51 against which the several stator plates 19 may be positioned and spaced one from another by means of spacer washers and finally locked at the end by means of screw members 48 which engage with the threaded end 47. of the shaft 52. A ball bearing 46 may be provided for the end of the shaft carried in bearing member 44 secured in position by means of nut 45 engaging the screw threaded stem of the member 44 on the opposite side of the frame portion 2. The spring chuck 56 may be readily secured in position with reference to the plate 1 of the condenser frame by means of tongue 66 which projects into a groove 75 in the screw threaded portion 53 of the chuck 56. When the pedestal type of insulator asrepresented in Figures 11, 12 and 13 is employed as shown in enlarged cross section in Fig. 10, the insulators 40 may be interiorly threaded as represented at 40 to enable the screw threaded end 25" of the nut 25 to be screwed within the screw threads 40 to securely position the pedestal in position. The entire condenser may be mounted relative to a panel or other surface by means of screws and cooperating bushings 67, 69 and 70.

It will be observed that the condenser construction which I have described may be readil manufactured and assembled and that t e pedestal insulators insure a dielectric of high quality.

While I have described my invention in certain particular embodiments I desire that it be understood that modifications may be made and that I intend no limitations upon the invention other than those imposed by the scope of the appended claims.

What I claim and desire to secure by Let ters Patent of the United States is as folrows:

1. A variable condenser construction comprising in combination a pair of end plate portions, a plurality of stator plates positioned between said end plate portions. spacer members at opposite ends of said plates for positively spacingcach of said plates one from another and a plurality of pedestal insulators interposed between said end plates and said spacer members for supporting said stator plates apart from said end plate portions.

2. A variable condenser construction comprising in combination a pair of end plates, a plurality of posts interconnecting said end plates forming a frame, a plurality of stator plates carried within said frame, a pair of spacer members at opposite ends of said plates positively spacing said plates apart and a plurality of insulated posts interposed between said spacer members and said end plates.

3. A variable condenser construction comprising in combination a pair of fiat end plate members, a plurality of stator plates. a pair of spacer members at opposite ends of said plates operating to positively space said plates apart and a plurality of cylindrical insulators interposed between said spacer members and each of said plates for centrally positioning said spacer members between said end plates.

4. A variable condenser construction comprising in combination a pair of substantially flat end plates, a pair of arms extending from each of said plates. a bridge member interconnecting each of said pairs of arms, a plurality of stator plates, a spacer block positioned at opposite ends of said plates for positively spacing said plates apart and insulating means interposed between opposite ends of said spacer blocks and said bridge members and maintained under compression for centrally locating said stator plates intermediate said end plates.

5. A variable condenser construction comprising in combination a frame, a plurality of stator plates centrally located within said frame, a spacer block at opposite ends of said stator plates and insulation means interposed between said spacer, blocks and said condenser frame and maintained under compression for securing said stator plates in position intermediate said end plates.

6. A variable condenser construction comprising in' combination a frame, a plurality of stator plates centrally located within said frame, a spacer block at opposite ends of said stator plates and a pair of pedestal insulators interposed between opposite ends termediate said of each of said spacer blocks and said end plates for securing said stator plates inter mediate said end plates.

7. A variable condenser construction com prising in combination a frame, a plurality of stator plates centrally located within said frame, a spacer block at opposite ends of said stator plates and short cylindrical insulators interposed between opposite ends of said spacer blocks and said end plates for securing said stator plates intermediate said end plates.

8. A variable condenser construction com of stator plates centrally located within saidframe, a spacer block at opposite ends of said stator tplates, a vitreous post interposed between said spacer blocks and said con- Y denser frame and maintained under com pressioniforj securingsaid stator plates in position intermediate said end plates and means binding'said end-plates together.

10. A variable condenser construction comprising inj combination a pair of substantiallyfl-at end plates, a pair of arms extending from each of said lates, a bridge member interconnecting sac of said pairs of arms, a plurality of stator plates, a

- spacer block positioned at opposite ends of said plates for ositivel apart, a cup s haped evice carried intermediate the length of said bridge members, a corresponding cup shaped device carried on each end of said spacer blocks and insulating means interposed between said cup spacing said plates LM M shaped devices and maintained under compression for centrally locating said stator plates intermediate said end plates.

11. A variable condenser construction comprising in combination a pair of end plates, a plurality of posts interconnecting said end plates forming a frame, a plurality of stator plates carried within said frame, a pair of spacer members atopposite ends of said plates positively spacing said plates apart, a resilient cup shaped device positioned adjacent opposite ends of said end plates, a similar resilient cup shaped device positioned on opposite ends of said spacer members and insulated posts interposed between each of said cup sha ed devices for substantially insulatingsai d stator plates from said end plates.

12. A rotor for a variable condenser comprising a rotar shaft, a bearing for opposite ends of said shaft, an enlarged longitudinal section forming art of said shaft, said section having a p urality of lateral grooves cut substantially throu b one half the diameter thereof, a pair of ongitudinal grooves connecting the opposite sides of said plurality of lateral grooves, a plurality of rotor plates adapted to be secured upon said rotary shaft, said rotor plates having an intermediate portion arranged to exten into said lateral grooves with the edge material of said portion adapted to be upset and filled within the space of said longitudinal grooves fonlockmg said plates with respect to said shaft.

13 In a variable condenser construction a frame comprising a pair of end plates, a rotor, bearings for said'rotor comprising a ball pivot carried by one of said end plates and a spring icollet chuck carried by the opposite end plate and having means for ad usting saidchuc k longitudinally on the axis of said sha? whereby said rotor plates ma be centra y positioned between said en plates.

SAMUEL COHEN. 

